[EnSkorSang]

There is noooooooooooooooo answer. But isnt writing a melody then writing another one that can be seen in the same song, kind of the same as succumbing to the verse/chorous structure.
If you wanna look at other structures, look no further than romantic/classical/baroque era music. or even 1940s music hall (george gershwin) music. YES, they are not at all the genre you want (probably) but, there was no such thing as verse/chorous then (cept in folk) so the structures vary..
transitions are often helped along with modulations and cadences, which can be wiki'd...
In modern music, an transition is often 'not' a transition however...often it is a change in tune (over the same basic structure) and rhythm associated with the lyrics..